Thesis
The effect of carbohydrate source in a urea-based liquid supplement on ruminal fermentation, methane production and performance of beef cows fed low-quality forage
Washington State University
Master of Science (MS), Washington State University
2015
Handle:
https://hdl.handle.net/2376/102457
Abstract
The project objective was to assess the feasibility of feeding a novel glycerol-urea liquid supplement to wintering beef cows fed low-quality forage. Four ruminally cannulated Angus cows were fed 11.9 kg of bluegrass straw (BGS), 0.91 kg chopped triticale mix (TRIT CHOP), and 0.91 kg supplement treatment in a Latin square with repeated measures. Treatments were alfalfa hay (CON), a molasses-urea liquid supplement (MOL), a glycerol-urea liquid supplement (GLY) and a mixture of the MOL and GLY (50/50). Rumen fluid samples were collected at 0, 2, 4, 8, 12, 16, 20, and 24 h after feeding to analyze pH, volatile fatty acid (VFA) profiles, and ruminal ammonia (NH3-N). Ruminal in situ incubation bags containing bluegrass straw (BGS) and triticale hay (TRIT) were removed at 0, 6, 12, 24, 48, and 72 h after feeding. The Latin square was repeated to assess enteric methane (CH4) emissions. Treatments did not increase dry matter (DM), organic matter (OM), ash and crude protein (CP) disappearance in BGS or TRIT. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) disappearance of BGS increased with MOL, GLY, and 50/50 treatment. Total VFA concentration, VFA profiles, and ruminal pH were not affected, but MOL, GLY and 50/50 increased NH3-N concentration. No difference in enteric CH4 production was observed between treatments. To assess cow performance, sixty late-gestation cows were blocked by weight into pens of five in a randomized complete block design and assigned to MOL, GLY, or 50/50 treatment. Cows were fed 86.1% TRIT, 7% TRIT CHOP and 7% liquid supplement treatment and were weighed every two weeks for 10 weeks. There was no difference in change in body weight (BW) as assessed by the BW * time interaction. Average difference in BW between the beginning and end of the trial was +3.31 ± 2.99 kg for MOL, +3.58 ± 5.48 kg for GLY, and +5.06 ± 2.86 kg for 50/50. The lack of difference in animal performance and improved fiber degradation in BGS indicate a glycerol-based urea supplement is an effective supplement for wintering cows as compared with the standard molasses-urea liquid supplement.
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Details
- Title
- The effect of carbohydrate source in a urea-based liquid supplement on ruminal fermentation, methane production and performance of beef cows fed low-quality forage
- Creators
- Ashley C. Conway
- Contributors
- Kristen A. Johnson (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Animal Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525130901842
- Language
- English
- Resource Type
- Thesis